U.S. patent application number 11/616676 was filed with the patent office on 2007-06-28 for endoscope apparatus and illuminating apparatus for endoscope.
Invention is credited to Yutaka KONOMURA, Kiyotomi OGAWA.
Application Number | 20070147033 11/616676 |
Document ID | / |
Family ID | 38193449 |
Filed Date | 2007-06-28 |
United States Patent
Application |
20070147033 |
Kind Code |
A1 |
OGAWA; Kiyotomi ; et
al. |
June 28, 2007 |
ENDOSCOPE APPARATUS AND ILLUMINATING APPARATUS FOR ENDOSCOPE
Abstract
This endoscope apparatus comprises an insertion section to be
inserted into a space to be inspected, a light emitting device for
illuminating inside of the space, a fluorescent member provided at
a tip-end of the insertion section and emitting fluorescent light
with light from the light emitting device as excitation light, a
light guide transmitting the light from the light emitting device
to the fluorescent member, a light branching member for branching a
part of the fluorescent light returned from the fluorescent member,
and an optical sensor for detecting light from the light branching
member, and when the illumination light becomes dark due to a
failure or removal of the tip-end section of the endoscope, an
image with low luminance is not displayed, glare at replacement of
the tip-end section can be reduced to improve workability and the
diameter of the insertion section can be thinned.
Inventors: |
OGAWA; Kiyotomi; (Tokyo,
JP) ; KONOMURA; Yutaka; (Tokyo, JP) |
Correspondence
Address: |
OSTROLENK FABER GERB & SOFFEN
1180 AVENUE OF THE AMERICAS
NEW YORK
NY
100368403
US
|
Family ID: |
38193449 |
Appl. No.: |
11/616676 |
Filed: |
December 27, 2006 |
Current U.S.
Class: |
362/230 |
Current CPC
Class: |
A61B 1/05 20130101; A61B
1/0669 20130101; A61B 1/0653 20130101 |
Class at
Publication: |
362/230 |
International
Class: |
F21V 9/00 20060101
F21V009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 28, 2005 |
JP |
2005-380211 |
Claims
1. An endoscope apparatus comprising: an insertion section to be
inserted into a space to be inspected; a light emitting device to
be a light source for illumination inside of the space to be
inspected; a fluorescent member provided at a tip-end of the
insertion section and emitting fluorescent light with light from
the light emitting device as excitation light; a light guide
provided in the insertion section and transmitting the light from
the light emitting device to the fluorescent member; a light
branching member for branching a part of the fluorescent light
returned from the fluorescent member through the light guide; and
an optical sensor for detecting light from the light branching
member.
2. The endoscope apparatus according to claim 1, further comprising
a light source control portion for controlling light emitting state
of the light emitting device by a detection result of the optical
sensor.
3. The endoscope apparatus according to claim 1, wherein the light
emitting device is a laser diode which emits laser light with an
oscillation wavelength in a range of 235 to 500 nm.
4. The endoscope apparatus according to claim 1, wherein the light
emitting device is a light emitting diode emitting light with an
oscillation wavelength of the main light emitting peak in a range
of 235 to 500 nm.
5. The endoscope apparatus according to claim 1, wherein at the
fluorescent member, fluorescent light emitted with light from the
light emitting device as excitation light is white light.
6. The endoscope apparatus according to claim 1, wherein the
fluorescent member includes a fluorescent body in which a
combination of the fluorescent light and the excitation light is
white light.
7. An endoscope apparatus comprising: an insertion section to be
inserted into a space to be inspected; a light emitting device to
be a light source for illuminating inside of the space to be
inspected; a tip-end optical adapter which can be detachably
attached to the tip-end of the insertion section; a fluorescent
member provided at the tip-end optical adapter and emitting
fluorescent light with light from the light emitting device as
excitation light; a light guide provided in the insertion section
and transmitting light from the light emitting device to the
fluorescent member; a light branching member for branching a part
of the fluorescent light returned from the fluorescent member
through the light guide; and an optical sensor for detecting light
from the light branching member.
8. The endoscope apparatus according to claim 7, further comprising
a light source control portion for controlling light emitting state
of the light emitting device by a detection result of the optical
sensor.
9. The endoscope apparatus according to claim 7, wherein the light
emitting device is a laser diode which emits laser light with an
oscillation wavelength in a range of 235 to 500 nm.
10. The endoscope apparatus according to claim 7, wherein the light
emitting device is a light emitting diode emitting light with an
oscillation wavelength of the main light emitting peak in a range
of 235 to 500 nm.
11. The endoscope apparatus according to claim 7, wherein at the
fluorescent member, fluorescent light emitted with light from the
light emitting device as excitation light is white light.
12. The endoscope apparatus according to claim 7, wherein the
fluorescent member includes a fluorescent body in which a
combination of the fluorescent light and the excitation light is
white light.
13. An illuminating apparatus for an endoscope comprising: a light
emitting device to be a light source for illumination inside of the
space to be inspected; a fluorescent member for emitting
fluorescent light with light from the light emitting device as
excitation light; a light guide for transmitting the light from the
light emitting device to the fluorescent member; a light branching
member for branching a part of the fluorescent light returned from
the fluorescent member through the light guide; and an optical
sensor for detecting light from the light branching member.
14. The illuminating apparatus for an endoscope according to claim
13, further comprising a light source control portion for
controlling light emitting state of the light emitting device by a
detection result of the optical sensor.
15. The illuminating apparatus for an endoscope according to claim
13, wherein the light emitting device is a laser diode which emits
laser light with an oscillation wavelength in a range of 235 to 500
nm.
16. The illuminating apparatus for an endoscope according to claim
13, wherein the light emitting device is a light emitting diode
emitting light with an oscillation wavelength of the main light
emitting peak in a range of 235 to 500 nm.
17. The illuminating apparatus for an endoscope according to claim
13, wherein at the fluorescent member, fluorescent light emitted
with light from the light emitting device as excitation light is
white light.
18. The illuminating apparatus for an endoscope according to claim
13, wherein the fluorescent member includes a fluorescent body in
which a combination of the fluorescent light and the excitation
light is white light.
Description
[0001] This application claims benefit of Japanese Patent
Application No. 2005-380211 filed in Japan on Dec. 28, 2005, the
contents of which are incorporated by this reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an endoscope apparatus
which can illuminate a space to be inspected and an illuminating
apparatus for an endoscope.
[0004] 2. Description of the Related Art
[0005] An endoscope apparatus has been widely used for observing
inside of a living body and a machine. As a light source for the
endoscope apparatus, a lamp with relatively large power consumption
such as a halogen lamp, a xenon lamp and a metal halide lamp has
been used. Recently, an endoscope apparatus has been developed
using a semiconductor light-emitting device with low power
consumption such as a light emitting diode (LED) and a laser diode
(LD) as a light source. For example, an endoscope apparatus for
fluorescent observation using an LD as a light source is proposed
in Japanese Patent No. 3194660. Also, an endoscope apparatus for
transmitting laser light from the LD to a fluorescent member
provided at a tip-end section by an optical fiber and illuminating
inside the space to be inspected with white light converted by the
fluorescent member from the light is proposed in Japanese
Unexamined Patent Application Publication No. 2005-205195.
SUMMARY OF THE INVENTION
[0006] One of endoscope apparatuses according to the present
invention comprises an insertion section to be inserted into a
space to be inspected, a light emitting device to be a light source
for illuminating inside of the space to be inspected, a fluorescent
member provided at a tip-end of the insertion section and emitting
fluorescent light with light from the light emitting device as
excitation light, a light guide provided in the insertion section
and transmitting the light from the light emitting device to the
fluorescent member, a light branching member for branching a part
of the fluorescent light returned from the fluorescent member
through the light guide, and an optical sensor for detecting light
from the light branching member.
[0007] Another one of the endoscope apparatuses according to the
present invention comprises an insertion section to be inserted
into a space to be inspected, a light emitting device to be a light
source for illuminating inside of the space to be inspected, a
tip-end optical adapter which can be detachably attached to the
tip-end of the insertion section, a fluorescent member provided at
the tip-end optical adapter and emitting fluorescent light with
light from the light emitting device as excitation light, a light
guide provided in the insertion section and transmitting the light
from the light emitting device to the fluorescent member, a light
branching member for branching a part of the fluorescent light
returned from the fluorescent member through the light guide, and
an optical sensor for detecting light from the light branching
member.
[0008] An illuminating apparatus for an endoscope according to the
present invention comprises a light emitting device to be a light
source for illuminating inside of the space to be inspected, a
fluorescent member for emitting fluorescent light with light from
the light emitting device as excitation light, a light guide for
transmitting the light from the light emitting device to the
fluorescent member, a light branching member for branching a part
of the fluorescent light returned from the fluorescent member
through the light guide, and an optical sensor for detecting light
from the light branching member.
[0009] Other features and advantages of the present invention will
be made apparent from the description below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an appearance diagram showing an outline of an
endoscope apparatus of a first embodiment of the present
invention;
[0011] FIG. 2 is a block diagram of the endoscope apparatus in FIG.
1;
[0012] FIG. 3 is a flowchart of light source control after lamp
switch-on in the endoscope apparatus in FIG. 1;
[0013] FIG. 4 is a block diagram of the endoscope apparatus of a
second embodiment of the present invention;
[0014] FIG. 5 is a block diagram of the endoscope apparatus of a
third embodiment of the present invention showing a state where a
tip-end optical adapter is removed;
[0015] FIG. 6 is a sectional view of the tip-end optical adapter
which can be detachably attached to the tip-end of an insertion
section of the endoscope apparatus in FIG. 5; and
[0016] FIG. 7 is a sectional view of the tip-end optical adapter
attached to the tip-end of an insertion section of the endoscope
apparatus in FIG. 5;
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Embodiments of the present invention will be described using
the attached drawings.
[0018] First, a first embodiment of the present invention will be
described using FIGS. 1 to 3.
[0019] As shown in FIG. 1, an endoscope apparatus 1 of this
embodiment comprises in outline a control device 3 incorporating a
control portion for controlling the entire device and a light
source portion for illuminating the inside of the space to be
inspected, a monitor 4 connected to the control device 3 for
observation, an elongated insertion section 5 to be inserted into
the space to be inspected, an operation portion 6 located at the
base end side (hand side of an operator) of the insertion section 5
and gripped by the operator for operating the insertion section 5,
and a flexible universal cord 7 extended from the operation portion
6 and connected to the control device 3.
[0020] The endoscope apparatus 1 is an industrial endoscope
apparatus with which an image of the space can be observed by the
monitor 4 by inserting the insertion section 5 into the space to be
inspected such as an inside of a machine or image data of the image
can be taken in. And the device with the same configuration as
above can be applied to an endoscope apparatus for observing not
inside the machine but inside a living body. In this case, the
space to be inspected is the inside of a living body.
[0021] The insertion section 5 comprises a tip-end section 8
incorporating an image pickup device for forming an observation
image of a subject for capturing an image and a light source
portion, etc., a bending section 9 formed capable of being bent
with a plurality of bending pieces consecutively connected capable
of pivotal rotation, and a flexible section 10 formed by an
elongated flexible members. The bending section 9 is bent by
operating a bending knob 11 disposed on the operation portion 6. In
the control device 3, a main switch 35, which is a power switch of
the entire endoscope apparatus 1, and a lamp switch 36, which is a
switch of the light source portion, are arranged.
[0022] Describing the internal configuration of the endoscope
apparatus 1 by FIG. 2, inside the tip-end section 8, there are
provided an objective optical system 20 for forming an observation
image of a subject, a CCD 21 of an image pickup device made of a
charge coupled device in which the observation image is formed and
the observation image is converted to an electric signal, a
fluorescent member 22 for emitting illumination light for
illuminating the inside of the space to be inspected as a light
source portion, and an illumination optical system 23 for
controlling light of the illumination light.
[0023] The tip-end section 8 and the operation portion 6 are
connected to each other by the bending section 9, the flexible
section 10 and moreover, the operation portion 6 and the control
device 3 are connected to each other by the universal cord 7. And
into the bending section 9, the flexible sections 10 and the
universal cord 7, a video signal line 24 connected to the CCD 21
and an optical fiber 28 as a light guide are inserted. The optical
fiber 28 is connected to the fluorescent member 22 with the tip-end
side disposed at the tip-end section 8, and the base end side is
faced with a focus position of a light collecting optical system
27b.
[0024] The control device 3 comprises a video signal processing
portion 25 to which a video signal line 24 is connected and a light
source portion, and the light source portion has an LD control
portion 30 (hereinafter described as LD), which is a light source
control portion for drive-controlling an laser diode as a light
emitting device 26, the LD 26, a light collecting optical system
27a disposed in front of the LD 26, a light collecting optical
system 27b, a light splitter 29, which is a light branching member
disposed between the light collecting optical systems 27a and 27b,
a light collecting optical system 27c disposed on the side of the
light splitter 29, a photo diode (hereinafter described as PD) 33
as an optical sensor disposed at the focus position of the light
collecting optical system 27c, and a light detection portion 34
which takes in an output signal of the PD 33 and outputs the light
detection signal to the LD control portion 30.
[0025] The LD 26 is a laser diode which can emit blue laser light
with the oscillation wavelength of 445 nm, for example, and
disposed at the focus position of the light collecting optical
system 27a.
[0026] The light splitter 29 is comprised by two right angle
prisms, and on an inclined face of one of the prisms a reflective
film 31 with wavelength selectivity is vapour-deposited. And the
inclined faces of the two prisms are bonded into a cube shape.
[0027] The reflective film 31 is a thin film which transmits blue
laser light outputted by the LD 26 and reflects light with a
wavelength longer than that. An end face of the light splitter 29
on the light collecting optical system 27b side to which the light
enters from the fluorescent member 22 is made as an input end 29b.
An end face on the light collecting optical system 27a side to
which the light of the LD 26 enters is made as an output end 29a.
An end face on the light collecting optical system 27c side on the
PD 33 side is made as an output end 29c.
[0028] The fluorescent member 22 is a fluorescent member emitting
fluorescent light of red light and green light with the blue laser
light by the LD 26, which is the light emitting device, as
excitation light. The fluorescent light by the red light and green
light is mixed with the blue laser light diffused in the
fluorescent member 22 to become white light and illuminates inside
the space to be inspected through the illumination optical system
23.
[0029] The optical fiber 28 has its base end section located at the
focus of the light collecting optical system 27b and the tip-end
section is connected to the fluorescent member 22.
[0030] In the endoscope apparatus 1 having the above-mentioned
configuration, an image of the inspection subject illuminated by
the light source portion in the state where the main switch 35 is
on and the lamp switch 36 is on is converted to a video signal at
the CCD 21 and inputted to the video signal processing portion 25
through the video signal line 24. The video signal obtained at the
video signal processing portion 25 is converted to a TV signal and
outputted to the monitor 4 and displayed thereon.
[0031] At the light source portion of the endoscope apparatus 1,
the LD 26 is lighted under control of the LD control portion 30 by
turning on the lamp switch 36. A blue laser light with the
wavelength of 445 nm is diffused and emitted from the LD 26, and
enters as parallel light from the light collecting optical system
27a for collecting light into substantially parallel light to the
output end 29a of the light splitter 29. Since the blue laser light
having entered from the output end 29a is transmitted through the
reflective film 31, most of the light is emitted from the input end
29b.
[0032] The blue laser light emitted from the input end 29b of the
light splitter 29 is focused on the base end section of the optical
fiber 28 by the light collecting optical system 27b and irradiates
the fluorescent member 22 through the optical fiber 28.
[0033] At the fluorescent member 22, fluorescent light of red light
and green light is emitted with the blue laser light as excitation
light by action of a fluorescent body included in the fluorescent
member 22. The red light and the green light are mixed with the
blue laser light transmitted through the fluorescent member 22 and
white light is emitted from the fluorescent member 22 so that it
passes through the illumination optical system 23 and illuminates
the space to be inspected. The illumination light is reflected by
the inspection subject and its subject image passes through the
objective optical system 20 and is taken in and forms an image on
an image forming face of the CCD 21.
[0034] On the other hand, a part of the white light from the
fluorescent member 22 reaches the base end side through the optical
fiber 28 and enters the light splitter 29 from the input end via
the light collecting optical system 27b. In that incident light,
the light with the wavelength longer than that of the blue laser
light outputted by the LD 26 is reflected by the reflective film 31
and emitted from the output end 29c as detection light. The
detection light enters the PD 33 through the light collecting
optical system 27c, and a detection signal is outputted from the PD
33. The detection signal is taken into the LD control portion 30
through the light detection portion 34.
[0035] The LD control portion 30 determines if the detection signal
is equal to or above a predetermined level (level corresponding to
a luminance state enabling observation). The LD control portion 30
recognizes that the LD 26, the optical fiber 28 and the fluorescent
member 22 are in the normal operating state and the space to be
inspected is in the illuminated state capable of being observed
based on the determination. And continuation of observation or
photographing by the endoscope apparatus 1 is permitted.
[0036] However, if there is some nonconformity in the tip-end
section 8 of the insertion section 5, the optical fiber 28 or the
LD 26, or if white light to the base end side disappears due to
removal of the tip-end section 8 or drops below a predetermined
level, the drop of the detection output is detected by the PD 33,
and the LD control portion 30 immediately stops light emission of
the LD 26 or switches to a low output state to an extent that the
laser light is not emitted, and then notify the operator that the
endoscope apparatus is not capable of or suitable for observation.
At that time, it is possible to instruct stop of output of the
image signal with low luminance to the video signal processing
portion 25.
[0037] The above-mentioned LD control processing operation by the
LD control portion 30 in the endoscope apparatus 1 will be
described using a flowchart of the LD control processing in FIG.
3.
[0038] After the main switch 32 is turned on, when on-operation of
the lamp switch 36 is detected by the LD control portion 30, the LD
control processing shown FIG. 3 is started, and the LD 26 is
lighted at step S1 so as to start illumination of the space to be
inspected. At step S2, stabilization of output of the PD 33 is
awaited for a predetermined time T, 10 msec, for example, and then,
the input state of the light to the PD 33 is checked by the output
signal at step S3. It is checked if the value of the output signal
of the PD 33 is equal to or more than the predetermined value or
not, or if a light amount corresponding to the state where the
space to be inspected is illuminated suitably for observation is
reflected from the fluorescent member 22, for example.
[0039] If it is confirmed that the output of the PD 33 is equal to
or more than the predetermined value, light emission of the LD 26
is continued, and the check at step S3 is repeated. If the output
of the PD 33 is decreased and it is confirmed that nonconformity
occurs at the tip-end section 8 of the insertion section 5, the
optical fiber 28 or the LD 26, or that the incident light amount to
the PD 33 is decreased by removal of the tip-end section 8 or the
like and the value falls below the predetermined value, for
example, the program goes on to step S4, where the LD 26 is turned
off and this routine is ended.
[0040] In the processing at step S4, the LD 26 may be controlled so
that the LD 26 is not turned off but the luminance is lowered to
continue lighting in the dimmed state not emitting the laser. By
controlling in this way, a failure of the LD 26 itself and a
failure of the other sections can be distinguished.
[0041] As mentioned above, according to the endoscope apparatus 1
of this embodiment, if the fluorescent member 22 is removed due to
breakage of the tip-end section 8 of the insertion section 5 or the
optical fiber 28 is broken by action of a large external force on
the insertion section 5, for example, such a state is detected by
the PD 33 from the decrease of light amount from the fluorescent
member 22. And the light emission of the LD 26 can be stopped or
brought into the dimmed state by the LD control portion 30 so that
the failure at the tip-end section of the endoscope is notified to
the user. At the same time, display of an image with lowered
luminance by dark illumination can be avoided.
[0042] Also, at replacement work of the fluorescent member 22 or
the optical fiber 28, when the tip-end section 8 is removed, by
stopping or decreasing the light amount of light emission of the LD
26 as above, glare can be prevented when the user looks at the
tip-end of the insertion section, which facilitates the replacement
work.
[0043] Moreover, since only one optical fiber 28 can function both
as a light guide for illumination and light guide for fluorescent
light detection, there is no need to provide an optical sensor or a
light guide exclusively for fluorescent light detection in the
insertion section 5 any more, by which the diameter of the
insertion section 5 can be thinned.
[0044] This embodiment is put into practice as an electronic
endoscope having a flexible insertion section 5 for electrically
transmitting an image. However, not limited to this, the
above-mentioned light source portion can be also applied to a fiber
scope having a flexible insertion section and transmitting an image
by an image guide fiber. Also, the above-mentioned light source
portion can be also applied to a rigid endoscope having a rigid
insertion section and transmitting an image by a relay lens system,
which can exert the same effect. In this embodiment, the optical
fiber 28 is used as a light guide for transmitting the laser light.
However, by having a blue LED as the light emitting device and
applying an optical fiber bundle bundling a plurality of optical
fibers instead of the optical fiber 28, the same effects can be
obtained.
[0045] Moreover, in this embodiment, the light source portion is
incorporated in the control device 3. However, not limited to this,
it is also possible to configure such that an optical connector is
disposed at the base end side of the optical fiber 28 and
detachably connected as an illuminating apparatus for an endoscope
having the light emitting device, light collecting optical system,
the light branching member, the optical sensor, and the LD control
portion through the optical connector in the state separate from
the control device 3.
[0046] Next, an endoscope apparatus of a second embodiment of the
present invention will be described using a block diagram of the
endoscope apparatus of this embodiment in FIG. 4.
[0047] In an endoscope apparatus 1A of this embodiment, as shown in
FIG. 4, an optical fiber coupler 37 with 1-input (input end 37b),
2-output (output ends 37a, 37c) is applied as the light branching
member in the light source portion to the endoscope apparatus 1 of
the first embodiment in place of the light splitter 29. The same
components as those in the endoscope apparatus 1 of the first
embodiment are given the same reference numerals and differences
will be described below.
[0048] In a control device 3A of the endoscope apparatus 1A of this
embodiment, one end of an optical fiber 39a is arranged in the
vicinity of a focus of the light collecting optical system 38 for
collecting blue laser light with the wavelength of 445 nm, for
example, diffused and emitted from the LD 26 as shown in FIG. 2.
The other end of the optical fiber 39a is connected to the output
end 37a of the optical fiber coupler 37. To the input end 37b of
the optical fiber coupler 37, the base end side of an optical fiber
39b is connected. The tip-end side of the optical fiber 39b is
connected to the fluorescent member 22 arranged at the tip-end
section of the insertion section 5. To the output end 37c of the
optical fiber coupler 37, one end of the optical fiber 39c is
connected, while to the other end of the optical fiber 39c, the PD
33, which is an optical sensor, is connected.
[0049] In the case of illumination of the inside of the space to be
inspected, the laser light emitted from the LD 26 is irradiated to
the fluorescent member 22 via the light collecting optical system
38, the optical fiber 39a, the optical fiber coupler 37 and the
optical fiber 39b, and the inside of the space to be inspected is
illuminated by white light. On the other hand, a part of the white
light from the fluorescent member 22 enters the PD 33 from the
output end 37c of the optical fiber coupler 37 via the optical
fiber 39c, and a detection signal is obtained. The detection signal
of the PD 33 is inputted to the LD control portion 30 through the
light detection portion 34.
[0050] Control operation or the like by the LD control portion 30
when the fluorescent member 22 is removed by breakage of the
tip-end section 8 of the insertion section 5 or the optical fiber
39b is broken by action of a large external force on the insertion
section 5 or at part replacement of the insertion section 5 is the
same as that in the first embodiment.
[0051] The effect by the endoscope apparatus 1A of this embodiment
is the same as that of the first embodiment, and particularly since
the light branching member is made more compact than the first
embodiment and the light collecting optical system for input/output
with respect to the light branching member is simplified, it has an
effect that the device is made compact.
[0052] In the endoscope apparatus 1A of this embodiment, the
optical fiber coupler 37 is used as the light branching member, but
if a light branching waveguide is used in place of that, the same
effect can be obtained.
[0053] In this embodiment, too, the light source portion is
incorporated in the control device 3A, but not limited to this, it
may be so configured that the illuminating apparatus for an
endoscope incorporating the light emitting device, the optical
fiber coupler, the optical sensor, and the LD control portion is
detachably attached to the endoscope apparatus in the state
separate from the control device 3A.
[0054] Next, an endoscope apparatus of a third embodiment of the
present invention will be described using FIGS. 5 to 7.
[0055] In an endoscope apparatus 1B of this embodiment, the optical
fiber coupler 37 as the light branching member is also applied to
the endoscope apparatus 1A of the second embodiment as shown in
FIGS. 5, 7, but they are different from each other in the point
that a tip-end optical adapter 40 is made attachable to a tip-end
section 8B of an insertion section 5B in the detachable state. The
same components of the endoscope apparatus 1A of the second
embodiment as those of the endoscope 1 in the first embodiment are
given the same reference numerals and only differences will be
described below.
[0056] At the tip-end section 8B of the insertion section 5B of the
endoscope apparatus 1B, the CCD 21 as the image pickup device, a
protective cover glass 51 for CCD protection and an optical-fiber
protective cover glass 52 disposed at the tip-end section of the
optical fiber 39b are arranged. Moreover, on the outer
circumference of the tip-end section 8B, a male thread section 8a
for attaching the tip-end optical adapter 40 and a positioning
groove 8b for the tip-end optical adapter are provided.
[0057] On the other hand, the tip-end optical adapter 40 comprises
a substantially columnar adapter body 43, a retaining ring 44 in
the substantially cylindrical shape and a ring-shaped retainer
45.
[0058] In the adapter body 43, the objective optical system 20 for
forming a subject image on the CCD 21, the fluorescent member 22
for emitting fluorescent light with the laser light from the LD 26
as excitation light, and the illumination optical system 23 in
front of the fluorescent member 22 for illuminating white light
emitted from the fluorescent member 22 into the space to be
inspected are arranged. Moreover, on the outer circumference
section, a male thread section 43a, an outer circumferential
engagement section 43b in the rear of the male thread, and a
positioning projection 43c projecting toward the CCD side are
provided.
[0059] The retaining ring 44 has an inner circumferential
engagement section 44b and a female thread section 44a on the inner
circumference in the rear and is rotatably attached to the adapter
body 43 by fitting the inner circumferential engagement section 44b
into the outer circumferential engagement section 43b.
[0060] The retainer 45 is fixed to the front part of the adapter
body 43 to which the retaining ring 44 is mounted by screwing and
bonding a female thread section 45a to the male thread section 43a.
In this state, the retaining ring 44 is prevented from being
removed from the adapter body 43.
[0061] The above-mentioned tip-end optical adapter 40 is attached
to the tip-end section 8B of the insertion section 5B of the
endoscope apparatus 1B by screwing. In detail, as shown in FIG. 7,
the positioning projection 43c of the adapter body 43 is fitted
into the positioning groove 8b of the tip-end section 8B of the
insertion section 5B. When the retaining ring 44 is screwed with
the male thread section 8a and the female thread option 44a, and
moreover, the outer circumferential engagement section 43b and the
inner circumferential engagement section 44b are brought into
contact in the axial direction and the retaining ring 44 is fixed
to the tip-end section 8B, the tip-end optical adapter 40 is
attached to the tip-end section 8B. In this attachment state, the
objective optical system 20 is located opposite in front of the CCD
21, and the fluorescent member 22, the illumination optical system
23 are located opposite in front of the optical fiber 39b.
[0062] The tip-end optical adapter 40 can be removed from the
tip-end section 8B of the insertion section 5B by loosening the
thread sections 8a, 44b.
[0063] In the state where the tip-end optical adapter 40 is
attached to the tip-end section 8B, the laser light emitted from
the LD 26 passes through the light collecting optical system 38,
the optical fiber 39a, the optical fiber coupler 37 and the optical
fiber 39b, and is irradiated to the fluorescent member 22. At the
fluorescent member 22, white light including the laser light with
the laser light as excitation light is irradiated toward the space
to be inspected.
[0064] On the other hand, a part of the white light emitted from
the fluorescent member 22 goes through the optical fiber 39b, the
optical fiber coupler 37 and the optical fiber 39c, and is guided
to the PD 33, its detection output is inputted to the LD control
portion 30 through the light detection portion 34 connected to the
PD 33, and the lighting control of the LD 26 is executed.
[0065] If the tip-end optical adapter 40 is removed while the LD 26
is lighted, since the excitation light is not irradiated to the
fluorescent member 22 any more, the white light stops emitting and
the light guided by the PD 33 is decreased. And when the fact is
recognized by the LD control portion 30 that the light amount
detected at the light detection portion 34 falls below the
predetermined value, the LD control portion 30 stops driving of the
LD 26 or brings it into the dimmed state or the light emitting
state to the extent that laser light is not emitted.
[0066] According to the endoscope apparatus 1B of this embodiment,
the same effect as that of the second embodiment is exerted, and
particularly since the tip-end optical adapter 40 is replaceable,
replacement of the fluorescent member 22, the objective optical
system 20 and the illumination optical system 23 is easy. And by
replacing the fluorescent member 22 by another florescent member,
the illumination light with the wavelength suitable for the space
to be inspected can be switched to the state capable of
irradiation. Also, by replacing the objective optical system 20,
the characteristic of the objective optical system 20 can be
changed so that an optimal view angle, observation direction and
focal depth according to the inspection subject can be
selected.
[0067] Moreover, when the tip-end optical adapter 40 is removed,
since lighting of the LD 26 is stopped or brought into the dimmed
state, an operator can replace the tip-end optical adapter without
sensing a glare. Also, in the above dimmed state, it can be
determined if the LD 26 is defective or not.
[0068] For attachment of the tip-end optical adapter 40 to the
tip-end section 8B, locking structure by screws or engagement of
notches and projections can be employed other than the
above-mentioned screwing of threads.
[0069] The LD 26 applied as the light emitting device in each of
the above-mentioned embodiments is a laser diode which can emit
blue laser light with the oscillation wavelength of 445 nm, but it
may be an LD emitting blue laser light with the oscillation
wavelength in a range of 235 to 500 nm or ultraviolet laser light.
Moreover, a light emitting diode (LED) may be applied in place of
the LD, and a light emitting diode emitting blue light with the
oscillation wavelength of the main light-emitting peak in a range
of 235 to 500 nm or ultraviolet ray can exert the same effect.
[0070] If the light emitting device is an LD emitting the
ultraviolet laser light or an LED emitting the ultraviolet ray as
above, the fluorescent member 22 emits white fluorescent light with
the light emitted by the light emitting device as excitation light.
Also, if the light emitting device is a blue-light LED, the
fluorescent member 22 emits red light and green light with the blue
light as excitation light, and white fluorescent light mixed with
the blue light is emitted.
[0071] According to the endoscope apparatus or the illuminating
apparatus for an endoscope of the present invention, when the
illumination light becomes dark due to a failure, removal or the
like of the endoscope tip-end section, an image with low luminance
is not displayed, glare at replacement of the tip-end section is
reduced so as to improve workability and the diameter of the
insertion section can be thinned.
[0072] The present invention is not limited to each of the above
embodiments, but various variations are possible in a range not
departing from its gist in practice. Moreover, inventions in
various stages are included in each embodiment, and various
inventions can be extracted in appropriate combinations of the
disclosed plurality of constituent features.
[0073] For example, even if some constituent features are deleted
from all the constituent features shown in each embodiment, if the
problems described in the problems to be solved by the invention
can be solved and the effects described in the effect of the
invention can be obtained, the configuration from which the
constituent features are deleted can be extracted as the
invention.
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